                At present, 3GPP2 (3rd Generation Partnership Project 2) is considering proposals using single frequency networks (SFN) for enhancing the “CDMA2000 High Rate Broadcast-Multicast Packet Data Air Interface Specification” (3GPP2 C.50054-0/ TIA-1006) to provide higher data rates to users. (3GPP2 may be contacted via www.3gpp2.com.) In the enhancement, one or multiple sites transmit the same broadcast contents at the same time. With enhanced receivers, the broadcast signals from different base transceiver stations (BTSs) can be effectively combined. The proposals under consideration include: “Enhanced Broadcast-Multicast for HRPD” (C30-20040607-060), “Updates to the Enhanced HRPD Broadcast Proposal” (C30-20041206-0xx), “Response to actions items on Qualcomm's Enhanced Broadcast Multicast Proposal” (C30-20031006-0xx), “A backward compatible CDMA-based enhanced broadcast multicast (EBM) system for HRPD” (C30-20041019-011), and “Derivation of Channel Estimation Error Model for CDMA EBM Evaluation Methodology” (C30-20041206-022).        
Each of these proposals provide increased data rates along with some (but not all) additional advantages that include backwards compatibility with existing High Rate Packet Data (HRPD)/1XEV-DO (DO) transceivers, no inter-block interference, an FDM (frequency division multiplexed) pilot orthogonal to the data symbols, a single receiver which can handle a unicast and efficient broadcast service, and a simple channel estimator. Since none of the present proposals provide all of these advantages in a single solution, it would be desirable to have a method and apparatus for providing enhanced broadcast-multicast service (BCMCS) that was able to provide all of these advantages.
Specific embodiments of the present invention are disclosed below with reference to FIGS. 1-7. Both the description and the illustrations have been drafted with the intent to enhance understanding. For example, the dimensions of some of the figure elements may be exaggerated relative to other elements, and well-known elements that are beneficial or even necessary to a commercially successful implementation may not be depicted so that a less obstructed and a more clear presentation of embodiments may be achieved. Simplicity and clarity in both illustration and description are sought to effectively enable a person of skill in the art to make, use, and best practice the present invention in view of what is already known in the art. One of skill in the art will appreciate that various modifications and changes may be made to the specific embodiments described below without departing from the spirit and scope of the present invention. Thus, the specification and drawings are to be regarded as illustrative and exemplary rather than restrictive or all-encompassing, and all such modifications to the specific embodiments described below are intended to be included within the scope of the present invention.